From StarWars.com:
"Now in the StarWars.com video player: A never before released animatic of a Revenge of the Sith deleted scene. The script originally had a scene in which Obi-Wan Kenobi ventures into the dragon pens of Utapau to find a mount to explore the sinkhole city. He chooses the most gregarious of the lizards, Boga. The scene never made it far past the animatic stage. In this early cut, Ben Burtt provides the voiceover for Kenobi and the aliens, and Boga's gender is different from the final."